The low-level design
On This Lesson 4 topics
This lesson is planned. The outline below lists the topics it will cover. The full lesson has not been published yet.
In this lesson
write an LLD a team can build from, including the unhappy paths.
Planned topics
- An LLD refines one HLD component: responsibilities, internal modules, data model, sequence flows, and configuration.
- Error and edge cases are first-class: timeouts, retries, duplicate messages, partial failures, and what the user sees.
- Include non-functional specifics: expected load, timeouts, retry limits, idempotency rules.
- Test: could a delivery lead estimate it without asking what is in scope?
Draft outline details
Demonstration
an LLD outline for order fulfillment with a sequence flow for "payment captured, ERP unavailable" and a table of failure cases with handling.
Check your understanding
What commonly goes missing in weak LLDs?
Show answer
Error handling and edge cases.
Practice
Apply this lesson with the module's lab, exercises and quiz.
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